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66 questions in this collection · Page 3 of 7
Breathing And Exchange Of Gases
Animal Kingdom
Excretory Products And Their Elimination
AI-generated explanation. Check against your textbook.
Statement I is false: the descending limb of the loop of Henle is permeable to water and relatively impermeable to electrolytes; the ascending limb is impermeable to water and actively transports ions. Statement II, in essence, is true: the proximal convoluted tubule is lined by a simple cuboidal epithelium with a brush border (microvilli) that increases the surface area for reabsorption. The exact NCERT phrase emphasizes the brush border and increased reabsorption capacity, though it uses cuboidal rather than columnar wording.
Brush border microvilli drastically increase the absorptive surface area, helping reabsorb filtered substances from the tubule into the blood.
Proximal convoluted tubule is lined by simple cuboidal epithelium with a brush border to maximize reabsorption.
Cell Cycle And Cell Division
| List-I (Sub phases of prophase I) |
List-II (Specific characters) |
|---|---|
| (A)Diakinesis | (I)Synaptonemal complex formation |
| (B)Pachytene | (II)Completion of terminalisation of chiasmata |
| (C)Zygotene | (III)Chromosomes look like thin treads |
| (D)Leptotene | (IV)Appearance of recombination nodules |
Human Health And Disease
| List-I | List-II |
|---|---|
| (A)Common cold | (I)Plasmodium |
| (B)Haemozoin | (II)Typhoid |
| (C)Widal test | (III)Rhinoviruses |
| (D)Allergy | (IV)Dust mites |
Excretory Products And Their Elimination
Biomolecules
AI-generated explanation. Check against your textbook.
According to NCERT, the substrate first binds to the enzyme’s active site to form the enzyme-substrate complex (E + S → ES), i.e., step E followed by A. Then the chemical bonds of the substrate are broken or rearranged to form products (D). The products are released from the enzyme (C), and the enzyme is free again to catalyze another reaction with a new substrate (B). So the correct sequence is E → A → D → C → B.
NCERT describes catalysis as a cycle where the enzyme returns to its original form after releasing products, ready to catalyze more substrate molecules.
Substrate binds to active site to form enzyme–substrate complex, then products are formed and released; enzyme is free again (E, A, D, C, B).
Cell Cycle And Cell Division
AI-generated explanation. Check against your textbook.
Statement I is true: both mitochondria and chloroplasts have double membranes. Statement II is also true: the inner mitochondrial membrane is highly selective and less permeable, more so than the inner membrane of chloroplasts, making it relatively less permeable. According to NCERT, these membranes regulate transport with transport proteins, keeping certain substances out and allowing others in, which explains the difference in permeability between the two organelles’ inner membranes.
Both organelles have their own DNA and ribosomes, supporting the idea that they were once independent organisms (endosymbiotic theory).
Double membranes surround mitochondria and chloroplasts; inner membranes are selectively permeable, controlling substances that enter the organelles.
Body Fluids And Circulation
| List-I | List-II |
|---|---|
| (A)P wave | (I)Heart muscles are electrically silent. |
| (B)QRS complex | (II)Depolarisation of ventricles |
| (C)T wave | (III)Depolarisation of atria. |
| (D)T-P gap | (IV)Repolarisation of ventricles |
Structural Organisation In Animals
| List-I | List-II | ||
|---|---|---|---|
| (A) | Unicellular glandular epithelium | (I) | Salivary glands |
| (B) | Compound epithelium | (II) | Pancreas |
| (C) | Multicellular glandular epithelium | (III) | Goblet cells of alimentary canal |
| (D) | Endocrine glandular epithelium | (IV) | Moist surface of buccal cavity |